S - Space Models

1. What is Spacemodelling?

Spacemodelling (SM ) is an airsport, a part of Aeromodelling, that deals with space models. It was invented by two Americans - Harry G. Stine (1928 - 1997), a rocket engineer, known as the “Father of Spacemodelling” and Orvil Carlslile, a shoemaker, in 1957. FAI started with it in 1962. The first, provisional rules were approved by FAI in 1964 and the official rules in 1968. In addition of being an air-sport Spacemodelling is also an applied science, good tools for technical education of young people etc. Spacemodelling is attractive for people whose age ranges from 10 to over 70 years.

2. Where do we have Spacemodelling?

Spacemodelling as an airsport is being practiced in: Bulgaria, Canada, China, Croatia, Czech Republic, Germany, Italy, India, Japan, Kazakhstan, Latvia, Lithuania, FYR Macedonia, Moldavia, Romania, Poland, Serbia, Slovakia, Slovenia, Spain, Switzerland, Russia, Turkey, Ukraine, United Kingdom, U.S.A. and Uzbekistan. It was also practiced for a short time in: Norway (1966), Egypt (1972), France (1980 – 90), Azerbaijan (1997), Australia (1980) and Republic of South Africa (2007). Recently, first contacts were made with Brazil, Cyprus, Greece and Sweden. Can you help to have Spacemodelling activities in your country?

3. What is CIAM Space Models Subcommittee?

Space Models Subcommittee (SM S/C) is a technical body of CIAM composed of at least six technical experts (including chairman) all from different countries. It deals with rule changes, technical development of SM and it takes care of international competitions. SM S/C was established in 1962. The first SM S/C chairman was Harry G. Stine - U.S.A. (1962 - 1972). His successors were: Otakar Saffek - CZE (1973-1977 and 1995-1996), Howard Kuhn - U.S.A. (1978 - 1995) and Srdjan Pelagic – SRB - starting 1996. The composition of the Space Models S/C for 2013/2014 can be found on the FAI website.

4. What is a space model?

A "Space model" is an aero-model that ascends into the air without the use of aerodynamic lifting forces against gravity; that is propelled by means of a space model engine; that includes a device for returning safely to the ground in a condition to fly again; and that is made of substantially non-metalic parts.

5. What classes are there in Spacemodelling?

There are ten main classes of space models.

S1 - altitude models,

S2 - payload altitude models,

S3 - parachute duration models,

S4 - boost/glide duration models,

S5 - scale altitude models,

S6 - streamer duration models,

S7 - scale models,

S8 - rocket glider duration models,

S9 - gyrocopter duration models,

S10 - flex wing duration models.

Each class, except class S7, has been subdivided related to engine size. These are Event Classes:

Event class

Total impulse

A/2

0,00 - 1, 25 Newton Seconds ( Ns )

A

1,25 - 2,50 Ns

B

2,51 - 5,00 Ns

C

5.01 - 10,00 Ns

D

10,01 - 20,00 Ns

E

20,01 - 40,00 Ns

F

40,01 - 80,00 Ns

In addition to these there are three provisional classes:

S6A/P – Streamer target time duration competition

S11/P - Rocket powered aircraft and spaceship

S12/p – Time duration triathlon tournament.

6. What are the construction requirements for Spacemodelling?

Construction of a space model shall be of wood, paper, rubber, breakable plastics and without substantial metallic parts. Models of classes S1, S2, S3, S6, S9 and S10 must have minimum diameter of 30 mm of enclosed airframe for a length of at least 50 % of the overall body length. In the case of S5 body diameter must be minimum 40 mm for at least of 20 % of overall body length. In case of S1 smallest body diameter, including boat tailing in the back section of the model shall not be less than 18 mm for at least 75% of the overall length of each stage including their back sections.

7. What engines do we use in Spacemodelling?

A space model engine shall be a solid propellant reaction engine that has all propellant ingredients preloaded into the casing in such a manner that they cannot easily be removed. All spacemodelling events shall be divided into sub-classes according the total impuls as follows:

Event class

Total impulse

A/2

1, 25 Newton Seconds ( Ns )

A

2,50 Ns

B

5,00 Ns

C

10,00 Ns

D

20,00 Ns

E

40,00 Ns

F

80,00 Ns

8. Where and how to start with Spacemodelling?

Easy! Gather a group of schoolchildren 12 - 13 years old and organize their technical meetings twice a week for two hours. Find some drawing paper to make bodies, balsa sheets of 1-1,5 mm for the fins and some styrofoam for nosecones. You already have general construction requirements - non-metallic parts, length 500 mm and diameter 40 mm. Total area of three or four fins shall be, for beginners, that of 2,5 cross sections of the body. Center of gravity (CG) of the model shall be 0,5 - 1,0 body diameter in front of center of pressure (CP) for that model. You can find roughly center of pressure if you cut a silhouette of the model of cardboard and balance it on the knife edge. To check is your model stabile and safe fix a piece of tread 1-1,5 m long at the center of gravity and rotate it over your head. If it follows trajectory with the nose cone heading forward - the model is stable and you can fly it safely. Buy some fabricated model rocket engines (start with A/2 or A engine class first). We wish you happy and successful flying! Send us a word about it!

9. Where to learn more on Spacemodelling?

You can choose three ways:

a) to read spacemodelling books or magazines,

b) to ask other spacemodellers for advices and

c) to go to spacemodelling competitions to see how the other people is doing that and to try yourself.

c) The only book on spacemodelling history: Prof Ioan Radu – International Spacemodelling – 2011published in Romanian and English. Available through the author atRadu Ioan astronautica_targoviste@yahoo.com